Effective transition cow management to maximize Internal Herd Growth. Thomas R. Overton, Ph.D. Department of Animal Science Cornell University

Transcription

1 Effective transition cow management to maximize Internal Herd Growth Thomas R. Overton, Ph.D. Department of Animal Science Cornell University

2 Our charge Devise and employ nutritional management strategies and nutritional tools to support metabolic adaptation to lactation Macromineral metabolism (manage DCAD) Glucose metabolism (provide fermentable carbohydrate) Fat metabolism (minimize BCS loss) Minimize potential negative effects of nonnutritional factors on metabolic adaptation to lactation Overcrowding Environmental stress (temp., ventilation) Infectious challenge/hygiene Grouping/regrouping Comfort

3 Big rocks from the nutritional side (common themes in our case farms) Manage DCAD Start with including low potassium forages in dry period diets Sufficient energy and protein intake from a dry period diet of moderately high nutrient density Thinner (within reason) is better Trends toward shortened dry periods and one-group nutritional strategies for dry cows

4 Effects of multiple stressors accumulate... Resources to stress response Breakpoint Heat stress Overcrowding Social stress Poor housing Metabolic stress Resources for production Drackley, 2002

5 Transition period indices relating to Internal Herd Growth Nondairy cull rate during first 60 days in milk Incidence of metabolic disorders Related to likelihood of high milk production Tied to reproductive performance

6 When Cows Leave the Herd (MN DHIA 10/96 10/01) Godden et al., % 10% 8% 6% 4% 2% 0% 624,614 Cows Leaving 5,749Herds % Cows Leaving That Left in the 21 Day Period DIM Interval

7 Nondairy cull rate during the first 60 days in milk Captures dead cows and cows sold for nondairy during first 60 days in milk Crude index of overall transition management Minnesota workers (previous slide) reported that 25% of cows that leave herds leave during the first 60 days in milk We look at the number of cows dead and sold for nondairy as a percentage of the number of calvings

8 Fresh cow loss as a percentage of calvings Typical values in well-managed herds are 10 to 12% (unacceptable) Best herds consistently average 5 to 6% Can be as high as 25% during train wrecks

9 Our case farms Dead and sold/calvings Farm Hanehan Durfee Adams 74/605 20/213 5/107 Percentage 12.2% 9.4% 4.7%

10 Incidence of metabolic disorders Combination of objective (retained placenta, displaced abomasum) and subjective (hypocalcemia, ketosis, metritis) Goals for each usually set by survey data

11 Transition cow survey Conducted by Buzz Burhans and colleagues 27 herds in Vermont and New Hampshire Over 600 cows in the dataset

12 Burhans et al., 2003

13 Problem Cow: Any problem (Dystocia, Mastitis, Abortion, Twinning, Stillbirths, Retained Placenta, Milk Fever, Digestive, Ketosis,Metritis,Edema, Displaced Abomasum, Off Feed) Metabolic Problem: (Milk Fever, Retained Placenta, Digestive, Ketosis, Displaced Abomasum and Off Feed) Infectious Problem: All cows with Mastitis, Metritis Energy Problem: (Digestive, Ketosis, Off Feed, Displaced Abomasum) Bad Calving: (Dystocia, Abortion, Twinnings, Stillbirths) Preventables: (Mastitis, Retained Placenta, Milk Fever, Digestive/Diarrhea, Ketosis, Metritis, DA, Off Feed) Burhans et al., 2003

14 Achievable goals for metabolic Milk fever -- < 5% disorders Retained placenta/metritis -- < 9% Displaced abomasum -- < 5% Clinical ketosis (blood BHBA > 27 mg/dl) -- < 5% Subclinical ketosis (blood BHBA > 14.4 mg/dl) -- < 15%

15 Our case farms Farm Hanehan Durfee Adams Milk fever 2.8 < RP 11.7 ~ Metritis 2.6 DA 5.6 ~ Ketosis 11.6

16

17 Framework for actualizing optimum nutritional management strategies on commercial dairy farms in the context of shortened dry periods

18 What are our nutritional goals and The Goals how do we achieve them? Moderately high DMI of well-formulated close-up diets while attempting to minimize extent of DMI decrease during the prepartum period How do we achieve them? Many herds still struggle to get ENOUGH dry matter intake in close-up cows (goal Holstein 26 to 28 lb/d of suggested close-up cow diet) In herds where close-up cows are consuming large amounts of DM ( > 30 to 33 lb/d), limit grain-type forages and other very palatable feeds to control intake within goal and complement with a consistent, low potassium forage source (preferably bulky) The challenge extent of DMI decrease extremely difficult to characterize in group-fed animals

19 Far-Off Dry Cows Dry-off until ~ 3 weeks pre-freshening Ration considerations NE L 0.59 to 0.63 Mcal/lb for maintenance BCS Do not want to overfeed (Dann et al., 2003) Stone, 2001

20 General goals for diet formulation for closeup cows and one-group dry cow systems up to 40 days Partial anionic Full anionic NE L, Mcal/lb 0.68 to 0.70 Metabolizable protein, g/d 1100 to 1200 NFC, % 34 to 36 Starch, % 19 to 21 Dietary Ca, g/d Dietary Ca, % Dietary P, % 0.30 to 0.35 Mg, % 0.40 to 0.42 Cl, % to 1.2 K, % < 1.3 < 1.3 Na, % 0.10 to 0.15 S, % to 0.4 Vitamin A (IU/d) Vitamin D (IU/d) Vitamin E (IU/d) Prefer use of organic trace elements, including organic Se

21 Advantages of shorter dry period Avoid forfeiting milk during late lactation Simplify dry cow management and decrease cost of dry cow housing (one dry cow group) Decrease sociological stress associated with multiple group changes, etc. More closely match dry period length with biologically required length (~ 25 days)

22 Summary of research on planned shorter dry period length Milk yield similar between cows managed for 40 vs. 60 days dry 65 herds in NY Coppock et al., 1974 Milk yield after 49- or 70-d dry periods comparable; 28- d dry reduced subsequent milk yield Sorensen and Enevoldsen, 1991 Milk yield comparable for cows managed for 60 vs. 30 to 35 d-dry periods Shairer, 2001; Bachman, 2002; Gulay et al., 2003 Comparable milk yield for 60 vs. 30-d dry; continuous lactation decreased subsequent milk yield (differences greater in primiparous cows) Annen et al., 2003; Rastani and Grummer, 2003

23 Cornell study Two commercial dairy farms (cows over 27 kg/d at 60 d before expected calving) Treatments 60 d dry period, label bst (two group dry cow management) 40 d dry period, label bst (moved to closeup group at 40-d dry Continuous lactation, label bst (stop bst at calving and resume during 9 th week of lactation) remained on lactating cow ration for the duration Fernandez et al., 2004

24 Least squares means for milk yield and milk composition during the first 6 months of the subsequent lactation for cows managed for 60, 40, or zero days dry. 1 Treatment Item 60-d dry 40-d dry 0-d dry SEM # of cows Average days dry Milk yield, kg/d 47.1 a 46.3 a 37.1 b 1.8 Fat, % Fat yield, kg/d 1.68 a 1.62 a 1.28 b 0.09 True protein, % 2.74 a 2.84 b 2.83 b 0.06 True protein yield, kg/d 1.31 a 1.30 a 1.06 b Means within a row with different superscripts differ, P <0.05. Fernandez et al., 2004

25 The Economics 60 versus 40 days dry Average milk yield, lb/d Item Marginal income Milk ($0.14/lb) $140 $168 Marginal expense Lactating diet $48 $56 Closeup diet $14 $14 Variable cost $15 $15 Total expenses $77 $85 Net per cow $63 $83

26 Current thinking on management considerations for 40-d dry period Either two-group or one-group nutritional strategies acceptable Marginal feed cost approximately $15 per cow for 20 additional days fed close-up diet One-group dry cow program fits better with shortened dry period Moderate NFC/energy close-up diet acceptable to feed for 40 d dry, regardless of DCAD strategy Continue to require far-off type diet to feed to cows with dry periods longer than 40 days